Hairstylists love to say you can reduce the times you shampoo to three times a week. But if you have fine and/or oily hair, you don't have to walk around looking dirty. Shampoo daily, but "thoroughly drench your hair with water before you lather up," says New Orleans dermatologist Mary P. Lupo. "Then concentrate on just the hair two inches closest to the scalp, since that's where sebum collects. And rinse really, really well under the coldest water you can stand." (Bonus: This will smooth the cuticle so frayed ends are less obvious.)

Stretching your hair with a brush while you incinerate it with a blow-dryer is not so hot for your hair's health. But you can fight frizz less harshly. A good-quality blow-dryer, like the Turbo Power Twin Turbo 3500, "dries so quickly that there really isn't time for the hair to overheat," says hairstylist Garren of the Garren New York salon, who recommends an ionic dryer with at least 2,000 watts of power. Ditch the big round brush for one with smooth, synthetic bristles. (We like the Sephora Bamboo Nylon Paddle Brush.) And at least try two things: Don't yank too hard on the hair and keep the nozzle as far away as possible. "Two inches would be acceptable," Lupo says.

Repeat after us and your hair will thank you: I will not overexpose my hair to the flatiron. Read the manufacturers' instructions and don't exceed the maximum suggested time. (It's typically about five seconds.) Using a flatiron only once a week and swearing off all but irons with ceramic plates, like the SalonTech Silicone 450 Flat Iron, helps further. Fans of chemical straightening should consider switching to a keratin treatment, which adds a smooth coating to each strand but doesn't mess with the cortex. (Liquid Keratin 30 Day Straight is a good at-home version.) Just steer clear of anything called "Brazilian straightening"; the treatment may contain dangerous levels of formaldehyde.

If you have the time and money to hit the salon every four weeks, great. Everyone else? Just get a good deep conditioner. "The ingredients aren't that different from those in your daily conditioner, but they're much more concentrated and they leave behind a smoothing film that won't wash off for days," explains cosmetic chemist Joseph Cincotta.